Rotary hook sewing machine



Aug. 3, 1937. c. c. SMITH ROTARY HOQK SEWING MACHINE 2 Sheets-Sheet 1 Filed March 12, 1935 INVENTOR: CZ/a/renca 6. Smith 5Q czar/mu; 0. 5mm,

Aug. 3, 1937. c. c. S MlTH 2,089,157

ROTARY HOOK SEWINGlMACHINE Filed March 12, 1935 2 Sheegs-Sheet 2 H (i Z WITNESSES: v INVENTOR:

A TTORNEYS.

an Aug. s," iesv no'rr noon! sh Clarence c. Smith, Chicago, m, pecial Mac worn-2 w pcration of oia Application n 12, rest, Serial! No. iaeis (cine-2st) comprehensively indicated ,at- 8, and Y Z @153 aims.

1 'Ehisinvention relates to sewing machines of t rotary hock type; and it is concerned more icularly with the lubrication of the rotary of such machines. 2

heretoiore devised for conducting lubricating oii Various reruns of lubricating systems have been to the rotary hooks of sewing machines, through holes in the work supporting surfaces of the ma- 1m: Such rotary hook lubricating systems are objectionable in. that, incident to replenishmentat frequent intervals, the oil is spilled on the work supporting surface with attendant spotting or st of the materialbeing sewed,

/ and further in that lint and dirt accumulate in" the open oil holes,,thereby clogging them and preventing how of the lubricant to the rotary hooks. v

invention is directed toward overcoming the drawbacks which have been pointed out I face of the machina'from which a tube leads and invention will be manifest. from the detailed de-' ve. objective I attain, as hereinafter more fully disclosed, through provision oi a lubricating system including 'an oil supply receptacle beyond the confines of the worksupporting sur conducts the oil to one end of a hollow horizontal it beneath the work supporting surface;

whcreon the rotary hook is mountedat the other end, and from the hollow of which'the oil is conducted through one or more ducts in the rotary hook to the raceway of the latter and the interengaging circumferential rib of the iated stationary bobbin casing. I

Other objects and attendant advantages .of this, 7

85 scription following of the attached a a wherein Fig. I showathe bottom view of a rotary hook sewing machine conveniently embo L myinvention. w 1

Fig. H is a fragmentary view showing chine in rear elevation.

Fig. m is a detail sectional ,view taken as indicated by the arrows III-HI in Fig. I and drawn toa larger scale.

the ma- Pig. IV. is a fragmentary detail sectional,view

' way 28 which engages the circumferential rib taken as indicated by the arrows IV -IV in Fig. V is a perspective'view of the rotaryhook.

of the-machine. I I

Fig. V1 is a perspective view cia plate element a part ofthe rotary hook; and 2 w is a detail sectional view taken as inbh the arrows VII-VII in Fig. m. 1 The se machine herein delineated is of the high speed rotary hook type comprising an elate hollow base i which aflords a fiat worksupporting surface 2, and an overhanging arm 8 extending horizontally from a standards at one end of the b; Journaled inge'ar housings i and t within the hollow of the base i. is *a longitudinal drive shaft '8' from which the fabric :12!- w l lnion Chic, Elli, a cor- The boss or hub of the rotary hook 9, see Has.

I and III, is secured by set screws it to the forward end of a-horizontal countershaft it within the base i beneath the work supporting surface 2. In accordance with my invention, the shaft ii is made tubular and is journaled for free ro-. tation in aligned bearing bushings l2 and it fixed respectively. in opposite side walls it and id of the gear housing 5, the bushing 82 being the longer of the two and partly accommodated in a bearing lug it integrally formed with the base i and the housing side wa M. It is to be particularly noted that the ft ii extends only part way into the rotary hook t with resultant formation within the huli of the latter of a central cavity in communication with the hollow of said shaft. Secured to the rotary hook shaft ii within the gear housing 5 is a smallspur gear pinion H which meshes with a relatively large spur gear wheel Eton the longitudinal drive shaft i, the shaft it being thus driven at correspondingly increased speed. Also as shown in Fig. one face of the gear wheel ill abuts hook 9 extend from the central cavity within the hub or boss not said hook tothe internal raceis or the associated stationarily held bobbin ,casing 26; Secured within the rotary hook- 9 by means of screws. 27, is a' plate 23" (Figs, III, VI and VII) having the form of a tri-arm which serves as a cover over the radial grooves 26 as well as over the end of, the central chamber in the boss or. hub at or the hook; with raultant formation of ducts for conducting lubricating oil from said chamber to the raceway 2d. The 7. number of the du'ctsfii may be increased or decreased if or required, and the grooves I formed in the cover plate 28 instead of in the,

spokeaoi the rotary hook 9 as illustrated by way of-example herein.

Located at a level above theshaft ii and beyond'the confines of the work supporting stirfaced of the base i, is a gravity feed oil receptacle in the form-of a cup 80, see Fig; H, which,

in the present instance, is supported-by a bracket 3i fastened to the standard d of the. machine.

The oil cup 36 is .preferably of a. conventional type having a sight glass 32, and adjusting means 38 at the top thereof whereby the flow of oil from the cup can be controlled. Leading downward from the oil cup is a tube N which enters the base I of the machine by way of the clearance aperture for the pedal rod 36 of the presser foot lifting arm ll, and which from thence extends horizontally to a\cap 3| secured by fluidtlght set screws 39 over the projecting end of the bearing bushing i3, seeFigs. III and IV. By virtue of this construction, oil is prevented from leaking out at the point of connection of the tube 34 with the shaft I I, any oil between said shaft and the bushing l3 draining into the gear housing 5 which thus serves as a collecting receptacle therefor.

I In practice, with the adjusting means to properly set,-oil is permitted to flow at a'predeterminedrate from the oil cup '30 through the tube through lint or dirt accumulations. My invention is effectively obviated.

Having thus described my invention, I claim: 1. In a sewing machine, a work supporting surface, a tubular horizontal shaft beneath the work supporting surface; bearings for the shaft in opposite end walls of a closed'oil catching recep- 40 tacle pendant from the supporting surface; the

outer end of one of saidbearings being closed over the corresponding end of the shaft; a gravity feed oil cup above the shaft beyond the confines of the work supporting surface; a tube leading from the oil cup and conducting the oil to the closed bearing aforesaid; and a rotary hook secured to the other end of the shaft, said hook" having an internal raceway in engagement with a circumferential rib on an associated stationary bobbin casing. and an .oil duct leading from the hollow of the shaft to the raceway.

- 2. In a sewing machine, a base. affording a work-supporting surface; a drive shaft joumaled beneath the work supporting surface; a tubular horizontal counter shaft also beneath said surface and driven from the drive shaft by intermeshing gears within a closed gear housing; bearings for the tubular shaft in opposite side walls of the gear housing, the outer end ofp'ne of which bearings is closed over the corresponding end of4h'e shaft; a gravityfeed oil 'cup above the tubular shaft beyond the confines of the work-supp rt surface; a tube leading from the oil cup and conducting the-oil to the closed bearing aforesaid;

and a rotary hook secured to the other end of the tubular shaft, said hook having an internal raceway in engagement with a circumferential rib on an associated stationary bobbin casing and an oil duct leading from the hollow of the tubular shaft to the raceway.

In a sewing machine, a tubular horizontal shaft; a gravity feed oil. supply above the shaft; a chamber around one end of the shaft; a tube leading from the oil supply to said chamber for continuous delivery of oil into the open end of the tubular shaft; and a rotary hook with a hub secured to the other end of the shaft, said hook having an internal raceway in engagement with a central rib on an associated stationary bobbin casing, a central distributing chamber within its hub in communication with the hollow of the surface; a chamber around one end of the shaft;

a gravity feed oil cup secured to the standard within the confines of the work-supporting surface; a tube leading from the cup to the aforesaid chamber for continuous delivery of oil into the open end of the tubular shaft; and a rotary hook with a hub secured to the other end of the shaft, said hook having an internal raceway in engagement with a-circumferential rib on an associated bobbin casing, a central distributing chamber within its hub in communication with the hollow of theshaft, and a duct leading from said distributing chamber to the raceway.

5. In a sewing machine, a tubular horizontal shaft; a gravity feed oil supply above the shaft; a chamber around one end of the shaft; a tube leading from the oil supply to the chamber for continuous delivery of oil into the open end of the .tubular shaft; a rotary hook with a hub secured to the other end of the shaft, said hook having an internal raceway in engagement with a central rib on an associated stationary bobbin casing, a central distributing chamber within its hub in communication with the hollow of the shaft, and an oil duct leading from said distributing chamber to the raceway; and'means whereby the flow of oil from the supply may be regulated.

6. In a sewing machine, a tubular horizontal shaft; a chamber around one end of the shaft; a gravity feed oil cup with regulatable control means above the shaft; a tube leading from the oil cup to the aforesaid chamber for continuous delivery of oil into the open end of the shaft; and a rotary hook with a hub secured to the other end of the shaft, said hook having an internal raceway in engagement with a circumferential rib onan associated stationary bobbin casing, a central distributing chamber within its hub in communication with the hollow of the shaft, and an oil duct leading from said distributing chamber to the raceway. f

7. In a sewing machine, a tubular horizontal shaft; a gravity feed oil supply above the shaft; a chamber around one end of the shaft; a tube leading from the oil supply to said chamber for continuous delivery of oil into the open end of the tubular shaft; and a rotary hook with a hub so,- cured to the other end of the shaft, said hook having circumferential bearing engagement with an associated stationary bobbin casing, and being formed with a central distributing chamber withcnsmmcn c. surrn. 

